Warren Bartley (“Bartley”) appeals the sentence imposed following his guilty-plea conviction for possession with intent to distribute marijuana. Bartley argues that the district court clearly erred by finding that he was responsible for two kilograms of cocaine in making its drug quantity determination because his responsibility for the cocaine was not supported by a preponderance of the evidence. For the first time in his reply brief, Bartley asserts that the district court violated his constitutional rights as set forth in Blakely v. Washington, — U.S. —, 124 S.Ct. 2531, 159 L.Ed.2d 403 (2004), because it based his sentence upon alleged cocaine deliveries to which he did not plead guilty and which were not proven to a jury beyond a reasonable doubt. Bartley additionally contends that the district court clearly erred by denying him a reduction for acceptance of responsibility. In one section of his brief, Bartley also appears to state that the delivery of cocaine was not part of the same course of conduct as his offense conduct, but Bartley does not make any further argument on this issue. To the extent that Bartley is attempting to raise this argument, it is not properly briefed and deemed abandoned. See Yohey v. Collins, 985 F.2d 222, 224-25 (5th Cir.1993).
Bartley was arrested in possession of approximately 22 kilograms of marijuana but no cocaine. However, when Bartley pled guilty the police officer testified that Bartley admitted after his arrest that he had been delivering both cocaine and marijuana for approximately one year. Following the conclusion of the officer’s testimony, Barley indicated that he agreed with the testimony.
At sentencing, a cooperating defendant testified that Bartley had delivered cocaine to him, and a police officer testified that Bartley admitted to delivering two kilograms of cocaine. Although Bartley testified that he had not delivered cocaine at sentencing, this did not make his earlier admissions unreliable to the extent that it could not be considered at sentencing. See United States v. Davis, 76 F.3d 82, 83-85 (5th Cir.1996). The cooperating defendant’s testimony was corroborated by Bartley’s admission and was sufficiently reliable to be considered. See United States v. Gaytan, 74 F.3d 545, 558 (5th Cir.1996). The district court was presented with conflicting statements from a witness and conflicting evidence and made a credibility determination that we will not disturb. See Davis, 76 F.3d at 85; United *700States v. Perez, 217 F.3d 323, 331-32 (5th Cir.2000). Accordingly, the district court’s drug quantity determination was not clearly erroneous.
Bartley’s Blakely argument is foreclosed by this court’s recent decision in United States v. Pineiro, 377 F.3d 464, 465-66 (5th Cir.2004). Furthermore, as Bartley denied relevant conduct that the district court found to be true at sentencing, the district court’s denial of acceptance of responsibility was not without foundation. See U.S.S.G. § 3E1.1, comment, (n.l(a)); United States v. Solis, 299 F.3d 420, 458 (5th Cir.2002).
AFFIRMED.